1. Ultrasound
D. Crowley, 2008

2. Ultrasound
To know what ultrasound is, and how this is used in hospitals

3. Ear Protectors
Stick in the ear protectors worksheet, and answer the questions in your book

4. Ear Protectors
Ear muffs with the headband have the greatest noise reduction, so would be most suited to a noisy environment
Ear protectors B and C reduce noise by the same amount (30dB)
Ear protectors A and B are likely to work loose
Ear protectors C, D and E are likely to be uncomfortable
Ear protectors A need give the least protection
Ear protectors A, B and C need clean hands, otherwise you risk microorganisms entering the ear causing ear infections
All the ear protectors have trapped air in
All the ear protectors have soft materials in them
The head is protected (falling materials etc…) so the ear protectors with the helmet are most suited for a building site

5. Ultrasound
Ultrasound is sound with a higher frequency than we can hear (i.e. above 20’000 hertz)
In nature some organisms, including bats, utilise ultrasound (they produce very high pitched squeaks, and convert the echoes into a picture of their surroundings, which is why they can fly at night)
Although we cannot hear ultrasounds, we can use them for a variety of things…

6. Industrial Cleaning
Ultrasound can clean delicate machines without the need to dismantle them
Ultrasounds can be directed to very precise areas and be uses to vibrate dirt away – this is also used for cleaning teeth (ultrasounds can remove tartar (this can lead to gum disease)

7. Kidney Stones
Ultrasound can also be used to break down kidney stones – high energy shockwaves can be aimed precisely at the kidney stone, breaking it down allowing the body to remove them
This means the patient does not need surgery, and is relatively painless

8. Pre-Natal Scanning
Ultrasound waves pass through some materials better than others
Different parts of the body reflect the sound waves differently (echoes)
A computer picks these reflected waves up, and processes them into a image so we can see inside the womb
It is not known for sure if ultrasound is entirely safe, but it is certainly safer than using X-rays!

9. Sonar Some animals have been using ultrasounds for millions of years
Humans have only recently taken advantage of ultrasounds, and although we cannot hear the sounds, we can use equipment to make and detect thee signals
Ultrasounds are produced, and a computer analyses how long the sound reflections (echoes) take to get back to a detector – this enables you to calculate the distance of certain objects

10. Sonar
Sonar equipment sends out a pulse of sound (ping) – the sound is reflected off objects, and the echo of the sound returns
The time taken for the echo to return is measured, and the distance calculated
This is used by boats to identify the depth of the seabed; fish finding; and by the military, especially within submarines (this is how they ‘see’ where they are going)

11. Ultrasound Scans
Complete the ultrasound scans worksheet

12. Ultrasound Scans Ultrasound
Ultrasounds are used to get a picture of an unborn foetus
X-rays show bones (and other dense materials)
Ultrasounds show the outside of the foetus (its outline)
X-rays can damage cells; ultrasound can provide moving pictures; ultrasound can show the outline of the foetus
The gel ensures sound waves can pass into the mother’s abdomen
Sex can be determined if a penis is visible. However the position the baby is in come sometimes obscure this
Moving pictures can identify if the baby is still alive (heart beating; general movement etc…)
Ultrasound can also be used to detect lumps in the body (tumours, gallstones etc…); removing tartar from teeth; breaking down kidney stones etc…